Allyl 2-cyanoacrylate-based orthodontic bracket adhesive

Abstract

An adhesive composition comprising Components A, B and C as follows: A. a polymerizable monomeric allyl 2-cyanoacrylate containing portion comprising 1. from about 75 to about 92 parts by weight of allyl 2-cyanoacrylate; 2. from about 1 to about 12 parts by weight of a difunctional monomer diester of an acid from the group consisting of acrylic and methacrylic acid and an aromatic diol; and 3. from about 3 to 20 parts by weight of a thickening agent selected from poly(methylacrylate-coacrylonitrile) polymers; B. from 0.1 to 3.0 weight percent based upon the weight of component A of a hydrophobic cyclic imino initiator selected from 2,4,6-tri(allyloxy)-S-triazine, tri(alkyloxy)-S-triazines having 1 to about 20 exocyclic carbon atoms, benzoxazole and substituted benzoxazoles; and C. an amount of an organic peroxide free radical providing compound sufficient to cause cross linking of the difunctional monomer diester with the allyl 2-cyanoacrylate.

We claim: 
     
       1. A solidified adhesive compound exhibiting hydrolytic stability which solidified adhesive compound results from combining components A, B and C as follows: A. a polymerizable monomeric allyl 2-cyanoacrylate containing portion prepared from 1. from 75 to about 92 parts by weight of allyl 2-cyanoacrylate;   2. from 1 to about 12 parts by weight of a difunctional monomer diester of an acid from the group consisting of acrylic and methacrylic acid and a diol having an aromatic nucleus; and   3. from 3 to about 20 parts by weight of a thickening agent selected from poly(methylacrylate-co-acrylonitrile) polymers;     B. from 0.1 to about 3 weight percent based upon the weight of component A of a hydrophobic cyclic imino initiator selected from the group consisting of 2,4,6-tri(allyloxy)-S-triazine, tri(alkyloxy)-S-triazines having 1 to about 20 exocyclic carbon atoms; and benzoxazoles having the formula ##STR4## wherein each R is the same or different and represents hydrogen, phenyl, alkyl of 1 to about 20 carbon atoms, chloro or bromo; and   C. an amount of an organic peroxide free radical providing compound sufficient to cause crosslinking of the difunctional monomer diester with the allyl 2-cyanoacrylate.   
     
     
       2. A solidified adhesive compound exhibiting hydrolytic stability which solidified adhesive compound results from combining components A, B and C as follows: A. a polymerizable monomeric allyl 2-cyanoacrylate containing portion prepared from 1. from 75 to about 92 parts by weight of allyl 2-cyanoacrylate;   2. from 1 to about 12 parts by weight of a difunctional monomer diester of an acid from the group consisting of acrylic and methacrylic acid an a diol having an aromatic nucleus; and   3. from 3 to about 20 parts by weight of a thickening agent selected from poly(methylacrylate-co-acrylonitrile) polymers;     B. from 0.1 to about 3.0 weight percent based upon the weight of component A of a cyclic imino initiator selected from the group consisting of 2,4,6-tri(allyloxy)-S-triazine and tri(alkyloxy)-S-triazines having 1 to about 20 exocyclic carbon atoms; and   C. an amount of an organic peroxide free radical providing compound sufficient to cause crosslinking of the difunctional monomer diester with the allyl 2-cyanoacrylate.   
     
     
       3. A solidified adhesive compound exhibiting hydrolytic stability which solidified adhesive compound results from combining components A, B and C as follows: A. a polymerizable monomeric allyl 2-cyanoacrylate containing portion prepared from 1. from 83 to 91 parts by weight of allyl 2-cyanoacrylate;   2. from 1 to about 8 parts by weight of a difunctional monomer diester of an acid from the group consisting of acrylic and methacrylic acid and a diol having an aromatic nucleus; and   3. from 7 to about 15 parts by weight of a thickening agent selected from poly(methylacrylate-co-acrylonitrile) polymers;     B. from 0.3 to about 2.5 weight percent based upon the weight of component A of a cyclic imino initiator selected from the group consisting of 2,4,6-tri(allyloxy)-S-triazine and tri(alkyloxy)-S-triazines having 1 to about 20 exocyclic carbon atoms; and   C. an amount of an organic peroxide free radical providing compound sufficient to cause crosslinking of the difunctional monomer diester with the allyl 2-cyanoacrylate.   
     
     
       4. A solidified adhesive compound exhibiting hydrolytic stability which solidified adhesive compound results from combining components A, B and C as follows: A. a polymerizable monomeric allyl 2-cyanoacrylate containing portion prepared from   
     
     
       1. from 83 to about 91 parts by weight of allyl 2-cyanoacrylate; 2. from 1 to about 8 parts by weight of a difunctional monomer diester selected from the group consisting of bisphenol A dimethacrylate, bis(hydroxyethyl terephthalate), diacrylate, and p-xylylene glycol bisacrylate;   3. from 7 to about 15 parts by weight of a thickening agent selected from poly(methylacrylate-co-acrylonitrile) polymer derived from an 80/20 to 20/80 weight % ratio of the methyl acrylate to acrylonitrile comonomer;   B. from 0.3 to about 2.5 weight percent based on the weight of component A of a cyclic imino initiator selected from the group consisting of 2,4,6-tri(allyloxy)-S-triazine and 2,4,6-tri(propoxy)-S-triazines; and   C. an amount of an organic peroxide free radical providing compound sufficient to cause crosslinking of the difunctional monomer diester with the allyl 2-cyanoacrylates.   
     
     
       5. The composition of claim 4 wherein the difunctional monomer diester is bisphenol A dimethacrylate, the thickening agent is poly(60 wt. % methyl acrylate-co-40 wt. % acrylonitrile) and the initiator is 2,4,6-tri(n-propoxy)-S-triazine. 
     
     
       6. The composition of claim 5 wherein the free radical providing compound is benzoyl peroxide. 
     
     
       7. The composition of claim 4 wherein the difunctional monomer diester is bisphenol A dimethacrylate, the thickening agent is poly(60 wt. % methyl acrylate-co-40 wt. % acrylonitrile) and the initiator is 2,4,6-tri(allyloxy)-S-triazine. 
     
     
       8. The compositon of claim 7 wherein the free radical providing compound is benzoyl peroxide.